Vane-type powder feeder



March 18, 1969 LYSAKOWSKI ET AL 3,432,884

VANE-TYPE POWDER FEEDER Filed Nov. '26, 1965 INVENTQRS EDWARD LYSAKOWSKI Jon/v KENNY BY Kama A-r'roR N EYS United States Patent Ofice Patented Mar. 18, 1969 48,334/64 US. (:1. 1s 9 3 Claims Int. Cl. B22f 3/18; 365g 31/00 ABSTRACT OF THE DISCLOSURE A rotary impeller in a housing receives powdered metal particles from an adjustable inlet port and accelerates the powder to a relatively high velocity and projects the powder from the housing through an outlet port which is arranged to direct the powder to the bight of a pair of compacting rolls.

This invention relates to feeders for feeding particulate material, more especially metal powder, into the roll gap of a compacting mill.

Heretofore, metal powder has been fed into the roll gap of compacting mills by direct gravity feed, by a screw feeder or by a carrier strip from which the compacted metal strip is subsequently separated. 7

These known feeding methods however suffer from the disadvantage that they are unable to feed powder to the roll gap at suflicient speed to overcome the phenomenon whereby air entrapped in the powder escapes therefrom in the region of the roll gap and tends to prevent powder entering the gap, especially at the high rolling speeds necessary for economical production of compacted metal strip.

According to another aspect of the present invention there is provided a device for projecting particulate material into the roll gap of a pair of compacting mill rolls, comprising a rotatable member provided with means for engaging particulate material fed into contact with said means and thereafter continuously projecting the material at a desired velocity into the roll gap.

The powder projecting means preferably comprises means rotatable within a housing having an inlet and an outlet, and provided with a plurality of substantially radial projections or vanes for engaging powder entering the inlet and porjecting it from the outlet at a desired velocity directly into the roll gap.

In order that the present invention may be well understood, there will now be described a preferred embodiment thereof, given by way of example, with reference to the accompanying diagrammatic drawings in which:

FIGURE 1 is a cross section through a powder feeder according to the invention; and

FIGURE 2 is a perspective view of a second embodiment of vaned impeller according to the invention.

Referring to FIGURE 1 of the drawings, a rotary impeller 2 is provided with equally spaced vanes 1 around its circumference, and is mounted on a rotatable shaft 3.

The impeller rotates within a cylindrical space 7 defined by the walls of the housing 5, and a powder inlet 4 and outlet 6 communicating with the space 7 are provided.

The annular space betwen the impeller 2 and the interior wall of the housing is thus divided up by the vanes into a number of pockets 8, so that when the shaft 3 rotates (anti-clockwise in the figure), powder fed from a hopper (not shown) into the inlet 4 will be entrained by the pockets 8 and accelerated to the peripheral speed of the moving pockets 8 and ejected from the outlet 6 into the roll gap 15 between rotary compacting rolls 16.

The rate at which powder is fed to the roll gap can be controlled by altering the speed of rotation of the shaft or by altering the cross-sectional area of the inlet orifice 4, an adjustable sliding gate 9 being provided for this purpose.

Althorugh eight vanes are shown on the impeller illustrated, the number may vary according to the ratio of maximum peripheral speed of the impeller to the maximum rolling speed.

FIGURE 2 shows an impeller 10 having thirty two vanes arranged in four coaxial sets 11, 12, 13, 14 of eight vanes each, with the vanes of each set staggered circumferentially relative to the vanes of the other three sets. This design gives a slightly higher powder throughput (at a given impeller speed) than the impeller shown in FIGURE 1.

Although the feeder illustrated in FIGURE 1 is shown as feeding the powder horizontally from the outlet it may obviously be adapted to feed vertically downwards when used in conjunction with vertical rolling mills.

The feeder described above has been found capable of feeding powder to the roll gap at speeds which are substantially higher than in any of the know conventional methods. In particular a sufiiciently high kinetic energy may be imparted to the powder particles to enable them to penetrate through the air escaping from the powder in the region of the roll gap, and a dense strip of exceptionally good quality can be obtained. Subject to this criterion, and of course to the criterion that the impeller throughput must be equal to or greater than the throughput of the compacted strip, the actual powder feeding speed employed may be lower than, equal to or greater than the rolling speed of the compacted strip.

Rolling speeds of up to 400 ft./min. are available at present using the feeding device described above, contrasted with the maximum rolling speed of about ft./min. possible with previously known feeding methods.

We claim:

1. Apparatus for producing an elongate article from particulate material, comprising: a pair of compacting rolls defining a bight; a housing having a rotor journalled therein, said rotor having circumferentially spaced radial projections thereon defining pockets therebetween; said housing having an inlet port arranged to direct said material to said pockets; and tangential outlet port means in said housing arranged to receive material projected from said pockets, by rotation of said rotor, and direct said projected material to said bight, said outlet port means defining a passageway of short length relative to the diameter of said rotor.

2. Apparatus as defined in claim 1 wherein said rotor is provided with :a plurality of coaxial sets of said projections, the projections of each set being circumferentially staggered with respect to the projections of adjacent sets.

3. Apparatus as defined in claim 1 wherein means are provided for varying the cross-sectional area of said inlet port whereby to, regulate the rate of feed of said material to said pockets.

(References on following page) References Cited UNTTED STATES PATENTS Fether 18-9 X Heck 18-9 Dasher et a1. 18-9 5 Menz et a1. 18-9 Oldham et a1. 18-9 X Jacobsen 198-128 X Andreas 198-128 2,141,512 12/1938 Carr 222-414 X 2,523,642 9/1950 Becker 222-414 X FOREIGN PATENTS 213,956 4/ 1924 Great Britain.

WILLIAM J. STEPHENSON, Primary Examiner.

US. Cl. X.R. 

